Membrane filtering device for screening oligopeptides with different molecular weights

The utility model relates to the technical field of separation and grading of oligopeptides, in particular to a membrane filtration device for screening oligopeptides with different molecular weights, which comprises an ultrafiltration tank consisting of an upper cylinder and a lower cylinder which are detachably connected, the top of the upper cylinder with a built-in stirring part is connected with an air inlet pipe, the air inlet pipe is connected with an external high-pressure air source, and the lower cylinder is connected with an air outlet pipe. A discharge pipe is arranged at the bottom of the lower barrel; a filter screen for transversely blocking the internal space of the ultrafiltration tank is also arranged in the lower barrel body, and an ultrafiltration membrane is loaded on a screen body of the filter screen. The device is simple in structure, can effectively improve the grading efficiency and realize step-by-step separation of polypeptides with different molecular weights by adopting the techn